Manufacture of writing-su rfaces



UNITED STATES PATENT OFFICE.

KARL ENGLER, OF HOME, KANSAS.

MANUFACTURE OF WRITING-SURFACES.

SPECIFICATION forming part of Letters Patent No. 407,649, dated July 23,1889.

Application filed March 23, 1889. Serial No. 304,552. (Specimens) T0 towhom it may concern:

Be it known that I, KARL ENGLER, of Home, in the county of Marshall andState of Kansas, have invented certain new and useful Improvements inthe Manufacture of \Vriting- Surfaces; and I do hereby declare thefollowing to be a full, clear, and exact description of theinvention,such as will enable others skilled in the art to which itpertains to make and use it, reference being had to the accompanyingdrawings, which form part of this specification.

Myinvention relates to an improvementin the manufacture ofwriting-surfaces; and the object of my invention is to provide a surfacefor blackboards, slates, &c., which can be written upon with a straw,tooth-pick, match, twigs from a tree, or other object, incontradistinction to surfaces heretofore produced, which require the useof a pencil.

A further object is to apply the compound to any smooth surfacesuch aswood, metal, paper, or cloth and thus adapt the writingsurface to allkind of uses.

In producing my invention I take wood, metal, cloth, paper, leather, orother substances, and paint it any color desired, using the ordinarypaint. WVhen this has become thoroughly dry, I give it a coating of apreparation consisting of one part boiled linseedoil, one part of emery,pumice-stone, or other fine gritty matter, and about one-half partspirits of turpentine.

The object upon which the writing-surface is to be formed may be givenas many coats of this preparation as may be thought desirable, andwhich. will vary according to the use to which it is to be subjected. Ifit is for a blackboard, a thick coating would be desirable. If appliedto cloth, leather, or paper for pocket use, a single coating would besufficient. \Vhen this has become thoroughly dried, by taking a match,tooth-pick, or other small object and using it as a pencil clear anddistinct lines will be made upon the face of the surface. These linesare readily and quickly erased by the use of a sponge, damp cloth, or inthe ordinary way of removing the marks from a slate.

The cloth, paper, or other flexible material that is treated with thiscompound does not become stiff or brittle, but is just as flexible as itwas before it was coated. It will be seen that since the materialtreated remains flexible many advantages arise over compounds heretoforeproduced. The top of a desk can be readily and cheaply coated with thiscompound by first painting it, letting it dry, and then givingit acoatof this compound. I-Ience my invention is especially adapted forconvertin g the upper surfaces of school-desks into writingsurfaces, formanufacturing small pocket-slates, or for the manufacture ofblackboards, copy-books, &c., and in each and every case producing asurface which can be written upon with an ordinary stick.

Having thus described my invention, I claim A compound to be applied topainted objects for producing a writing-surface that can be written uponwith an ordinary stick, consisting of linseed-oil, gritty matter, andspirits of turpentine, in about the proportions specified.

In testimony whereof I affix my signature in presence of two witnesses.

KARL ENGLER.

Vitnesses:

A. F. PHILLIPS, GEO. HAHN.

